an area within Nagano prefecture NE of Nagano city. Yamanouchi-cho encompasses the 3 main onsen areas of Yudanaka-Shibu onsen-kyou(湯田中渋温泉郷) and over a dozen other onsen spots, the Jigokudani Monkey Park(地獄谷野猿公苑), and Shiga Kogen(志賀高原), the #1 and largest ski resort in all of Japan. Photos below are from my whirlwind visit of the area before heading back to Tokyo.
The onsen hotel i stayed in is Kanaguya(金具屋) in Shibu-onsen(渋温泉). This almost 250yr old wooden onsen resort was the template for the spirit-filled onsen house in Miyazaki's famous anime Spirited Away(orig: Sen to Chihiro no Kamikakushi 千と千尋の神隠し).